The present invention relates to locking mechanisms for locking (i.e., preventing unauthorized rotation of) a rotary steering member such as a steering wheel, handlebar, etc. of a vehicle.
Conventional steering column locks use an actuator mechanism to drive a locking pin into and out of locking engagement with a steering shaft. Efficient transfer of motion can be accomplished by directly driving the locking pin back and forth. However, certain circumstances may arise in which the locking pin becomes substantially wedged against one of the recesses in the steering shaft. In order to account for this occurrence, the electric motor that drives the locking pin and the corresponding electric drive circuit for the motor must have current/power ratings substantially higher than what is required for normal operation (when the locking pin is not wedged). Also, complex gear reduction devices may be implemented in order to multiply the torque output of the motor. In either case, the locking device as a whole becomes more costly and complicated, and may generate excessive noise. Complicated control procedures may be used by a steering lock controller to make multiple attempts, and in some cases alter the drive signal to the electric motor, if it is determined that the motor has not successfully released the locking pin upon the initial attempt.